I. Field of the Invention
This invention relates to display systems wherein a laser generated image is projected for display. More particularly, this invention relates to laser recording and projection display systems wherein the use of achromatic polarizing cubes together with a single projector and a single laser deflecting and focusing system enables a first laser beam to be used to generate the images that are to be projected and a second laser beam to be used as a pointer with the projected image.
II. Description of the Prior Art
A laser recording and projection system is disclosed in U.S. Pat. No. 3,961,334 wherein a selectively deflected laser beam is utilized to generate an image on a metallized film. By backlighting the metallized film, the images recorded thereon can be projected upon a display screen. Such display systems are useful as online systems for the display of alphanumeric data, charts, map plotting, military training programs, and the like. As will be apparent, there are circumstances which make it desirable to be able to selectively scan a pointer over the projected image as an aid to the viewer. Preferably, such a pointer is projected along the same projection axis as the projected image. It is also desirable that the pointer have the capability of being automatically controlled. For reasons of economy and reliability, the pointer should use as much as possible of the existing projection system and incorporation of such a pointer into the system should not decrease the image brightness.
Accordingly, one object of this invention is to provide an improved laser recording and projection system.
Another object of this invention is to provide an improved laser recording and projection system having a pointer that is selectively controlled over the projected image.
A further object of this invention is to provide a display system wherein information is plotted and projected with a high efficiency light source.
Still another object of this invention is to provide a display system which enables the simultaneous plotting and projection of laser recorded information together with a laser pointer.
An additional object of this invention is to provide a laser recording and projection system wherein a non-polarized light source is split into two polarizations with one polarization then being rotated to correspond to the other polarization to obtain only one polarization of projection radiation that is compatible with a polarized projector.